NavigationRail is not shown in a parent without fixed height

[FeodorFitsner]

Internally NavigationRail is made of Column with Expand inside it.
It fails to render if put into a parent control without a fixed height.

Solutions:

1. Add expand=True to NavigationRail or set its height to a fixed value.
2. Put NavigationRail inside a control with expand=True or a fixed height.

The following code fails:

import flet
from flet import *
from flet import icons


def main(page: Page):
    page.add(
        Row(
            [
                NavigationRail(
                    selected_index=0,
                    label_type="all",
                    min_width=100,
                    min_extended_width=400,
                    leading=FloatingActionButton(icon=icons.CREATE, text="Add"),
                    group_alignment=-0.9,
                    destinations=[
                        NavigationRailDestination(
                            icon=icons.FAVORITE_BORDER,
                            selected_icon=icons.FAVORITE,
                            label="First",
                        ),
                        NavigationRailDestination(
                            icon_content=Icon(icons.BOOKMARK_BORDER),
                            selected_icon_content=Icon(icons.BOOKMARK),
                            label="Second",
                        ),
                        NavigationRailDestination(
                            icon=icons.SETTINGS_OUTLINED,
                            selected_icon_content=Icon(icons.SETTINGS),
                            label_content=Text("Settings"),
                        ),
                    ],
                    on_change=lambda e: print(
                        "Selected destination:", e.control.selected_index
                    ),
                )
            ],
        )
    )

flet.app(target=main)

The fix:

Add expand=True to Row control.